michael_cain writes: We have a whole-house fan that is our principle source of summertime cooling (high dry climate, cools off quickly when the sun goes down). On-off and fan speed are controlled by connecting the "hot" lead to one of two terminals on the electric motor. The current manual controls are a simple spring-driven timer in series with a SPDT switch that controls high and low speeds — only the "hot" lead goes to the switches. My wife would like an electronic control that can be given a sequence of times and speeds — high for two hours, low for three hours, high for one hour, etc. Any suggestions for commercial or DIY approaches to the problem? And safety issues to look out for in the case of DIY? I'm experienced with microcontroller programming and can fabricate simple circuit boards, but have never done anything that was hooked directly into 120 VAC.